Contraction of the abdominal muscles associated with movement of the lower limb

Background and Purpose. Activity of the trunk muscles is essential for maintaining stability of the lumbar spine because of the unstable structure of that portion of the spine. A model involving evaluation of the response of the lumbar multifidus and abdominal muscles to leg movement was developed to evaluate this function. Subjects. To examine this function in healthy persons, 9 male and 6 female subjects (mean age = 20.6 years, SD = 2.3) with no history of low back pain were studied. Methods. Fine-wire and surface electromyography electrodes were used to record the activity of selected trunk muscles and the prime movers for hip flexion, abduction, and extension during hip movements in each of these directions. Results. Trunk muscle activity occurring prior to activity of the prime mover of the limb was associated with hip movement in each direction. The transversus abdominis (TrA) muscle was invariably the first muscle that was active. Although reaction time for the TrA and oblique abdominal muscles was consistent across movement directions, reaction time for the rectus abdominis and multifidus muscles varied with the direction of limb movement. Conclusion and Discussion. Results suggest that the central nervous st stem deals with stabilization of the spine by contraction of the abdominal and multifidus muscles in anticipation of reactive forces produced by limb movement. The TrA and oblique abdominal muscles appear to contribute to a function not related to the direction of these forces.

Tenoxicam controls pain without altering orthodontic movement of maxillary canines

Arantes GM, Arantes VMN, Ashmawi HA, Posso IP To study the efficacy of tenoxicam for pain control, its potential for preemptive analgesia, and its influence on the orthodontic movement of upper canine teeth. This was a randomized controlled double-blind cross-over study. The patients were divided into three groups. Two groups received tenoxicam in daily doses of 20 mg orally for 3 days. Group A received the first dose of the drug before orthodontic activation and group B, just afterwards. Group C (control) received a placebo for 3 days. All groups had access to 750 mg of paracetamol up to four times a day. Three orthodontic activations were performed at 30-day intervals. Each patient belonged to two different groups. Pain intensity was assessed using a descriptive Pain Scale and a Visual Analog Scale. Private clinic; 36 patients undergoing bilateral canine tooth retraction. The statistical analysis did not show any difference in movement between the active groups and the control at any time. There was no statistical difference between the groups that received tenoxicam. Pain intensity in these groups was lower than in the placebo group. The difference in pain intensity between the active groups and the control was greatest at the assessment made 12 h after activation and it tended to zero, 72 h after activation. Tenoxicam did not influence orthodontic movement of the upper canines. It was effective for pain control and did not present any preemptive analgesic effect.

Feedforward contraction of transversus abdominis is not influenced by the direction of arm movement

Because the structure of the spine is inherently unstable, muscle activation is essential for the maintenance of trunk posture and intervertebral control when the limbs are moved. To investigate how the central nervous system deals with this situation the temporal components of the response of the muscles of the trunk were evaluated during rapid limb movement performed in response to a visual stimulus. Fine-wire electromyography (EMG) electrodes were inserted into transversus abdominis (TrA), obliquus internus abdominis (OI) and obliquus externus abdominis (OE) of 15 subjects under the guidance of real-time ultrasound imaging. Surface electrodes were placed over rectus abdominis (RA), lumbar multifidus (MF) and the three parts of deltoid. In a standing position, ten repetitions of shoulder flexion, abduction and extension were performed by the subjects as fast as possible in response to a visual stimulus. The onset of TrA EMG occurred in advance of deltoid irrespective of the movement direction. The time to onset of EMC activity of OI, OE, RA and MF varied with the movement direction, being activated earliest when the prime action of the muscle opposed the reactive forces associated with the specific limb movement. It is postulated that the non-direction-specific contraction of TrA may be related to the control of trunk. stability independent of the requirement for direction-specific control of the centre of gravity in relation to the base of support.

Mandibular Function is Severely Impaired in Systemic Sclerosis Patients

Aims: To evaluate the presence of temporomandibular disorders (TMD) in systemic sclerosis (SSc) patients and its possible association with the severity of skin involvement. Methods: The presence of TMD was evaluated in 35 SSc women and 30 age- and sex-matched healthy controls by means of the anamnestic (A(i)) and clinical (D(i)) Helkimo indices; the jaw mobility was further analyzed (M(I)). Skin involvement was scored by the Modified Rodnan Skin Score (MRSS). Results: Signs and symptoms of TMD were more frequent in SSc patients than in controls, the frequency distribution of the different clinical dysfunction indices differing significantly (P < .001) between patients (D(i)0 8.6%, D(i)I 48.6%, D(i)II 22.8%, and D(i)III 20%) and controls (D(i)0 50%, D(i)I 33.3%, and D(i)II 16.7%). Cyclophosphamide for severe and rapidly progressive cutaneous fibrosis was prescribed in six out of seven patients with severe signs (D(i)III), in contrast this treatment was indicated for only two out of 25 patients with mild to moderate signs (D(i)I and D(i)II, P <. 001). Impaired jaw mobility was more frequent in SSc patients than controls (P < .001). It was severe in 77.1% (M(I)II) and mild in 22.9% (M(1)I) of the cases, in contrast to controls (M(I)0 33.4%, M(I)I 53.3%, and M(I)II 13.3%; P < .001). Approximately half of SSc patients with severe (M(I)II) but none of those with mild impairment were on cyclophosphamide treatment for severe cutaneous fibrosis (P = .02). Conclusion: Severe signs of TMD according to the anamnestic and clinical Helkimo indices were very frequent in SSc patients. J OROFAC PAIN 2010;24:197-202

Impairments of movement kinematics in patients with Huntington's disease: A comparison with and without a concurrent task

This study aimed to quantify the efficiency and smoothness of voluntary movement in Huntington's disease (HD) by the use of a graphics tablet that permits analysis of movement profiles. In particular, we aimed to ascertain whether a concurrent task (digit span) would affect the kinematics of goal-directed movements. Twelve patients with HD and their matched controls performed 12 vertical zig-zag movements, with both left and right hands (with and without the concurrent task), to large or small circular targets over long or short extents. The concurrent task was associated with shorter movement times and reduced right-hand superiority. Patients with HD were overall slower, especially with long strokes, and had similar peak velocities for both small and large targets, so that controls could better accommodate differences in target size. Patients with HD spent more time decelerating, especially with small targets, whereas controls allocated more nearly equal proportions of time to the acceleration and deceleration phases of movement, especially with large targets. Short strokes were generally less force inefficient than were long strokes, especially so for either hand in either group in the absence of the concurrent task, and for the right hand in its presence. With the concurrent task, however, the left hand's behavior changed differentially for the two groups; for patients with HD, it became more force efficient with short strokes and even less efficient with long strokes, whereas for controls, it became more efficient with long strokes. Controls may be able to divert attention away from the inferior left hand, increasing its automaticity, whereas patients with HD, because of disease, may be forced to engage even further online visual control under the demands of a concurrent task. Patients with HD may perhaps become increasingly reliant on terminal visual guidance, which indicates an impairment in constructing and refining an internal representation of the movement necessary for its. effective execution. Basal ganglia dysfunction may impair the ability to use internally generated cues to guide movement.

Functional asymmetries in the movement kinematics of patients with Tourette's syndrome

Objectives-This study adopted a concurrent task design and aimed to quantify the efficiency and smoothness of voluntary movement in Tourette's syndrome via the use of a graphics tablet which permits analysis of movement profiles. In particular, the aim was to ascertain whether a concurrent task (digit span) would affect the kinematics of goal directed movements, and whether patients with Tourette's syndrome would exhibit abnormal functional asymmetries compared with their matched controls. Methods-Twelve patients with Tourette's syndrome and their matched controls performed 12 vertical zig zag movements, with both left and right hands (with and without the concurrent task), to large or small targets over long or short extents. Results-With short strokes, controls showed the predicted right hand superiority in movement time more strongly than patients with Tourette's syndrome, who instead showed greater hand symmetry with short strokes. The right hand of controls was less force efficient with long strokes and more force efficient with short strokes, whereas either hand of patients with Tourette's syndrome was equally force efficient, irrespective of stroke length, with an overall performance profile similar to but better than that of the controls' left hand. The concurrent task, however, increased the force efficiency of the right hand in patients with Tourette's syndrome and the left hand in controls. Conclusions-Patients with Tourette's syndrome, compared with controls, were not impaired in the performance of fast, goal directed movements such as aiming at targets; they performed in certain respects better than controls. The findings clearly add to the growing literature on anomalous lateralisation in Tourette's syndrome, which may be explained by the recently reported loss of normal basal ganglia asymmetries in that disorder.

Movement-related potentials in Parkinson's disease - Motor imagery and movement preparation

Movement-related potentials (MRPs) associated with voluntary movements reflect cortical activity associated with processes Of movement preparation and movement execution. Early-stage pre-movement activity is reduced in amplitude in Parkinson's disease. However it is unclear whether this neurophysiological deficit relates to preparatory or execution-related activity, since previous studies have not been able to separate different functional components of MRPs. Motor imagery is thought to involve mainly processes of movement preparation, with reduced involvement of end-stage movement execution-related processes. Therefore, MRP components relating to movement preparation and execution may be examined separately by comparing MRPs associated with imagined and actual movements. In this study, MRPs were recorded from 14 subjects with Parkinson's disease and 10 age-matched control subjects while they performed a sequential button-pressing task, and while they imagined performance of the same task. Early-stage pre-movement activity was present in both Parkinson's disease patients and control subjects when they imagined movement, but was reduced in amplitude compared with that for actual movement. Movement execution-related components, arising predominantly from the primary motor cortex, were relatively unaffected in Parkinson's disease subjects. However motor preparatory processes, probably involving the supplementary motor area, were reduced in amplitude overall and abnormally prolonged, Indicating impaired termination following the motor response. Further this impaired termination of preparatory-phase activity was observed only in patients with more severe parkinsonian symptoms, and not in early-stage Parkinson's disease.

Relationship between limb movement speed and associated contraction of the trunk muscles

Rapid shoulder movement is preceded by contraction of the abdominal muscles to prepare the body for the expected disturbance to postural equilibrium and spinal stability provoked by the reactive forces resulting from the movement. The magnitude of the reactive forces is proportional to the inertia of the limb. The aim of the study was to investigate if changes in the reaction time latency of the abdominal muscles was associated with variation in the magnitude of the reactive forces resulting from variation in limb speed. Fifteen participants performed shoulder flexion at three different speeds (fast, natural and slow). The onset of EMG of the abdominal muscles, erector spinae and anterior deltoid (AD) was recorded using a combination of fine-wire and surface electrodes. Mean and peak velocity was recorded for each limb movement speed for five participants. The onset of transversus abdominis (TrA) EMG preceded the onset of AD in only the fast movement condition. No significant difference in reaction time latency was recorded between the fast and natural speed conditions for all muscles. The reaction time of each of the abdominal muscles relative to AD was significantly delayed with the slow movement compared to the other two speeds. The results indicate that the reaction time latency of the trunk muscles is influenced by limb inertia only with limb movement below a threshold velocity.

Oral Mucosal Melanoma of the Mandibular Gingiva: A Case Report

Orla mucosal melanoma is rare and is reported to be more aggressive than cutaneous melanoma. The incidence of oral mucosal melanoma peaks at 41 to 60 years of age and the male to female ratio is 2 to 1. Preferred sites in the oral mucosa include the hard palate and maxillary alveolar crests. Risk factors have not been clearly identified, but melanotic pigmentation is present in one-third of patients prior to the diagnosis of melanoma. We report an unusual case of oral mucosal melanoma of the mandibular gingiva with the main characteristics of an in situ lesion and areas of superficial invasion in a 45-year-old woman. The patient was treated with surgical resection of the lesion and a 54-month follow-up shows no evidence of recurrence. Oral mucosal melanomas are aggressive neoplasms that may arise from prior pigmented lesions in the oral mucosa. Classification of these tumors is not well-established and the main prognostic factor appears to be lymph node compromise. The main treatment modality is surgical resection. Cutis. 2010;86:89-93.

Mandibular appliance modulates condylar growth through integrins

Functional orthopedic therapy corrects growth discrepancies between the maxilla and mandible, possibly through postural changes in the musculature and modulation of the mandibular condylar cartilage growth. Using Wistar rats, we tested the hypothesis that chondrocytes respond to forces generated by a mandibular propulsor appliance by changes in gene expression, and that integrins are important mediators in this response. Immunohistochemical analyses demonstrated that the use of the appliance for different periods of time modulated the expression of fibronectin, alpha 5 and alpha v integrin subunits, as well as cell proliferation in the cartilage. In vitro, cyclic distension of condylar cartilage-derived cells increased fibronectin mRNA, as well as Insulinlike Growth Factor-I and II mRNA and cell proliferation. A peptide containing the Arginine-Glycine-Asparagine sequence (RGD), the main cell-binding sequence in fibronectin, blocked almost all these effects, confirming that force itself modulates the growth of the rat condylar cartilage, and that RGD-binding integrins participate in mechanotransduction.